I found the times for Rollei RPX-D here, but only for one Ilford film and two Kodak films. Unless the developer comes with starting times for the full range of those manufacturers films, then I will not bother with it.

This developer appears to be the same as Rollei RHS developer, but at a much lower price. Perhaps Fotohuis can tell us more.

Both Rollei RPX-D and Rollei Supergrain are SPUR products. RPX-D has been made especially for pushing the Rollei RPX-100/400 films. Rollei Supergrain is an almost 1:1 copy of the Amaloco AM74 developer which was sold by Rollei-Maco before 2008 (when Amaloco Photochemicals the Netherlands closed the factory) OEM under L.P. Supergrain later Rollei High Speed. The Amaloco "brand name" was at the end bought by Nordfoto a competitor of Maco which gave Tetenal the order for some interesting Amaloco products remade in Germany.
Their Rollei Low Speed is an Udo Raffay CG-512 reference developer and the Rollei Low Contrast the Udo Raffay Film Low Gamma receipt.

Some products SPUR is selling under their own label. Like SD2525 which is also used by Adox for their "special" Silvermax developer. And you mentioned already PXD.

Fotohuis wrote:Both Rollei RPX-D and Rollei Supergrain are SPUR products. RPX-D has been made especially for pushing the Rollei RPX-100/400 films. Rollei Supergrain is an almost 1:1 copy of the Amaloco AM74 developer which was sold by Rollei-Maco before 2008 (when Amaloco Photochemicals the Netherlands closed the factory) OEM under L.P. Supergrain later Rollei High Speed. The Amaloco "brand name" was at the end bought by Nordfoto a competitor of Maco which gave Tetenal the order for some interesting Amaloco products remade in Germany.Their Rollei Low Speed is an Udo Raffay CG-512 reference developer.

Some products SPUR is selling under their own label. Like SD2525 which is also used by Adox for their "special" Silvermax developer. And you mentioned already PXD.

Thank you Robert. I believe that the RLS developer is a liquid Microdol type developer. Can you confirm this? I guess this is the developer to choose for very fine grain and resolution and Adox FX39 for high contour sharpness.

Now that Paterson no longer sell photo-chemicals, Nordfoto and Spur seem to be the only producers of customized film developers for special purposes.

CG-512 has been invented by Raffay many years ago. It took him 512 attempts in modifications hence the name. Suvatlar in Hamburg is dealing with his receipts. It is also a 24C developer and indeed like Microdol-X Ultra Fine Grain but not the same formulae.

Nordfoto is a commercial company only. Their Amaloco chemicals are produced by Tetenal.

Robert, have you ever made any direct comparisons with RHS/AM74 and FX39? Both are said to provide sharp negatives.
I want to try something sold as a liquid concentrate for a change rather than a developer sold as a dry powder to make a stock solution.

FX-39 has been transferred from Paterson to Adox. The bottle has the half content (volume) now and the price has been about doubled. 4x more expensive and for 0,25€ct/ltr. I can make FX-37 which has been published.
AM74 (later sold under L.P. supergrain and under Rollei label RHS) is from 1974 and was a formulae from Amaloco photochemicals in an answer on the new Kodak Tmax films. It is a semi-compensating type developer working in a wide range on a lot of films with great results however it had the disadvantage that in 35mm the Tri-X 400 and HP5+ had to many grain. Further it contains rather some Hydroquinone, in 1974 nothing serious about this chemical, now it is on a "Black" list for carcinogenic material in a high concentrate. Even still in a liquid form less harmfull however D76 and ID11 as powder has it in a higher concentrate too but D-76 is from 1927, nothing about environmental problems in that era.

About your question: FX-37 (39) is one of the sharpest developers together with FX-1 (Beutler), Tetenal Neofin Blau/Blue. Then you have AM74, Rodinal/R09, pyro type developers. For the last type it is extremely difficult to compare because any Pyro type developer reacts in a different way on each film in sharpness and stain. You have some excellent combinations with Pyrocat-HD, sharp and moderate grain. But for Tgrain type films you can use Xtol, FX-37/39, DD-X, Tetenal Ultrafin T-plus, Tmax dev., AM74 with very good results.

It's time to give some feedback from the developers I have tried recently. Both the Rollei RHS and Adox FX39 are excellent developers if you want the convenience of a liquid concentrate.
Of the two, the FX39 seems to give finer grain and smoother tones while maintaining good sharpness.